YELLOW-FACED BUMBLE BEE, Bombus vosnesenskii, gathers nectar from a tower of jewels. The Cameron study looked at three species of western bumble bees, including this species. (Photo by Kathy Keatley Garvey)

Bombus Bifarius

BOMBUS BIFARIUS, shown here at Bodega Bay, was one of three western species of bumble bees looked at in the Cameron study. Of the three, only B. occidentalis is in decline “and that one only in the western part of its range,” Robbin Thorp said. (Photo by Kathy Keatley Garvey)